After years of doing windshield repair I can tell you that damage to your windshield is often bigger than it looks. The first step in repairing a windshield is to assess the breakage by taking a probe and cleaning out any loose glass from the point of impact and also applying light pressure to the area around damage to make sure that there isn’t any more cracks that are not visible to the eye but only show up when the glass if flexed. One of the biggest reason for windshield repairs that failure is not doing this simple flexing technique and making sure there is not any hidden cracks. A good example of this would be if you had a star break and it had five legs coming of of it and the sixth leg was not visible until you applied pressure. Remember if there just one crack that does not get filled with resin the star break still has the same potential of spreading as if you never repaired the windshield in the first place.